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The improvement of reliability is one of the main benefits of distributed generation(DG) in the distribution network. It is important for a distribution company (DisCo) to specify which DG is more beneficial for reliability improvement. In general the participation of each DG in reliability improvement might be different. So, in this paper a method is proposed to reliability improvement allocation to DGs in the distribution network. The proposed method determines the participation of each DG in the reliability improvement index. The effectiveness of this method is verified through numerical results on a sample 33-bus system. (4 pages)

The technical and economical developments during last decades have established opportunity to create a new competitive distribution system based on modern power electronic technology. From technological point of view the LVDC system is a new concept in the field of electricity distribution. In general, two basic approaches have been reported for solving the AC-DC network power flow equations: sequential and unified methods. Similar to AC distribution networks, due to the large number of PQ buses and high r/x ratio, methods such as Newton Raphson and FAST Decoupled cannot be used in these systems; introduced methods also cannot be used in AC/DC distribution networks. In this paper, load flow calculations are studied in AC/DC distribution networks including a weakly mesh, in the presence of distributed generation and energy storage units, taking into account different converter control strategies, by backward forward sweep and compensation-based algorithms. (4 pages)

With the presence of distributed generation (DG) in electric distribution networks, distribution companies (DisCo) have the options to purchase energy from DGs units and/or directly from the wholesale electricity market. The DisCo's desired purchasing price of DG's energy depends on their impacts on network, and as well as wholesale market price. This paper proposes a new method to determine the minimum guaranteed price of DG's energy with consideration their impacts on loss. These prices are as efficient economical signal so that lead the investors to installation of DGs at buses with more positive technically impact on the distribution network. (4 pages)

The demand for higher quality and reliability of power distribution system, role of distribution system in reducing losses and pollutions have increased requirement for utilization of power electronic devices in distribution systems. LVDC system is one of the newest technologies in the field of distribution networks. In this paper, LVDC system's economic penetration rate in MV branches is studied for different load densities, types and different influences of distributed generation units in multiple configurations. Simulation results are obtained by using MATLAB software on a hypothetical network. (4 pages)

Reliable electric energy is one of the most important necessities for customers and there are high correlation between customer based reliability indices and customer satisfaction. Electric power interruptions have not only economics problems but also it makes social and mental difficulties. However customers’ sensitive is different against interruption. Culture and living stiles of customers have significant effects on their satisfaction from utilities. For consideration of customer view point against interruptions, it seems that Customer Dissatisfaction Index (CDI) should define and enter as a reliability index. Based on this index, reliability enhancement strategies can be planned for maximizing customer satisfaction index. In this paper for assessing customer dissatisfaction index, questionnaires are designed. As case study these questionnaires have been filled by domestic customers in Rasht, a big and costal city in north of Iran. Gathered data has entered in SPSS software and customers’ reply stochastic indices have obtained and analyzed. According to results, sharp threshold values for customer satisfied regarding reliability of supply were found. Results show customers’ sensitive for number and duration of outages and transient fault depends on time a day or seasons, in this paper time based Customer Dissatisfaction Index has been analyzed.

Maintenance of transformer is an activity which is done on non-defective transformers to reduce or eliminate the weak points. This is one of the main strategies in asset management. The aim of this work is to increase the useful life time of transformers and decrease their failure rates which will prevent their outages and troubleshoot problem. Over last years, many strategies have been presented for service and maintenance of distribution system components such as transformer. Which each of them depending on funding and liquidity of Distribution Company takes action about maintenance planning process. This paper, in addition of reviewing the existing methods in the service and maintenance of transformers, presents a new method which is based on distribution companies performance in Iran. In this method, determination of each transformer failure probability and priority is attempted for service and maintenance, according to available operation information. (4 pages)

A considerable increase in the penetration of distributed generation (DG) to the distribution networks leads to a higher possibility of malfunction of present protection schemes of these systems. One of the major problems caused by higher levels of DG penetration is the reduction of the relay reach or relay access. This problem relatively relieves using adaptive overcurrent protection techniques but in certain conditions, the minimum relay access reduces to less than 20 percent of line length, in the presence of DGs and adaptive current protection cannot be used. In this paper a combined adaptive protection method is presented, which applies overcurrent and undervoltage protection simultaneously. Function of the protection system improves because of different action areas of these two types of protection. The feasibility of the proposed method authenticated through simulation. (4 pages)

Proliferation of DC output type Distributed Energy Resource (DER) units in the utility power systems, mostly at the distribution voltage levels, and also recent advancement in the power electronics devices have motivated the integration of DC microgrids as an integral part of AC grids. LVDC system is one of the newest technologies in the field of distribution networks. In this paper, economic design of hybrid AC/DC distribution networks are studied for bipolar LVDC system configurations, area with different load densities and different penetrations of distributed generation sources, considering various kinds of loads. Optimal connection configuration of load points and Distributed Generations to the AC and DC substations candidate points is determined by genetic algorithm considering investment, loss and also customer interruption costs. Afterward, final structure of network is designed by branch exchange method. (4 pages)

Smart homes are residential buildings equipped with devices that coordinate with each other using communication infrastructure and sensors in order to manage residential energy consumption and satisfy inhabitants comfort. This paper presents a novel method to make an optimal decision about appliances scheduling based on predicted prices and inhabitants comfort. A fuzzy technique is applied to model the predicted price and customer comfort. Numerical study of implementing the method on appliances of a home is presented here. (4 pages)

This paper proposes a multi objective optimization to determine the optimal size and location of distributed generation in the distribution network to minimize load supply cost and enhance reliability improvement. In this paper the cost of DG investment, maintenance and operation is considered as well as the benefits of load supply cost reduction and reliability improvement. Also a new method is proposed in this paper to determine the nodal price. This nodal price is used to determine the actual value of load supply cost reduction. Finally particle swarm optimization is used to solve the optimization problem. (4 pages)